Eco-friendly dehydrogenation of dimethylamine-borane catalyzed by core-shell-looking tri-metallic RuNiPd nanoclusters loaded on white-flowering horse-chestnut seed

Generally, white-flowering horse-chestnut seed (WFHC) found in roadsides, parks and gardens, which spills around and causes environmental pollution, is defined as waste-bio material. This study is quite remarkable as it gives WFHC a new field of usage and literally prioritizes the environment. Here, waste-bio WFHC was tested as supporter for tri-metallic RuNiPd nanoclusters in the eco-friendly dehydrogenation of dimethylamine-borane (DMAB). Core-shell-looking tri-metallic RuNiPd@WFHC, with 264.09 ± 45.55 nm particle size, were in-situ synthesized throughout dehydrogenation of DMAB at 35.0 ± 0.1 °C. The WFHC and tri-metallic Ru_2.00Ni_1.86Pd_1.00@WFHC NCs were characterized by advanced analysis and their surface morphologies were studied in detail using adsorption models. The N₂ adsorption-desorption and logarithmic-Freundlich plots indicated that surface morphologies have heterogeneous multi-layer and typical Type-III isotherm with mesoporous surfaces. Also, detailed kinetic studies were actualized on the dehydrogenation of DMAB catalyzed by tri-metallic Ru_2.00Ni_1.86Pd_1.00@WFHC NCs with 158 h^?1 TOF value.     

HACCP在浓香菜籽油生产中的应用

为了保障浓香菜籽油的产品质量安全,采用HACCP体系对浓香菜籽油生产全过程进行生物、物理、化学的危害分析,确定关键控制点,制定预防措施,并对生产环节进行有效监控,制定纠偏措施,做好记录管理,为浓香菜籽油的安全生产提供借鉴。     

采动覆岩卸荷膨胀累积效应

地下煤层开采引起的岩层运动是一系列安全和环境问题的根源,研究采动岩层运动规律是安全、高效、绿色开采的重要基础。通过对岩层运动过程的研究,揭示了采动覆岩卸荷膨胀累积效应及其对岩层运动规律的影响机制。研究表明:采动覆岩经历了卸荷膨胀与再压实的动态过程。受关键层结构控制,上覆岩层由下向上成组破断运动,关键层破断前,阻断了上覆载荷向下方岩层的传递,导致其因卸荷而产生膨胀,包括碎胀与弹性膨胀。随着关键层破断高度增加,覆岩卸荷高度同步增大,因卸荷而膨胀的岩层总厚度不断增大;同时卸荷煤岩也受到已破断关键层载荷的压实作用,从而造成覆岩卸荷膨胀总量的不断变化。将这种覆岩卸荷膨胀总量随覆岩卸荷高度动态变化的现象定义为采动覆岩卸荷膨胀累积效应,进而建立了理论模型,并通过淮北海孜煤矿巨厚火成岩下采煤覆岩裂隙实测进行了验证。结果表明,采动覆岩卸荷膨胀累积效应对采动岩层运动规律产生了重要影响,如影响覆岩关键层下离层量,影响覆岩关键层贯通破断的高度,影响不同开采条件的地表下沉系数等。采动覆岩卸荷膨胀累积效应改变了对离层存在形式的传统认识,该效应的存在导致关键层下最大离层量一般小于采高的10%,覆岩可注浆充填空间并非传统认识上的“离层区”,而主要是注浆充填压力“压实”作用下将覆岩卸荷累积膨胀所转化出的那部分空间,该发现指导了覆岩隔离注浆充填绿色开采技术的创新研发及其在建筑物压煤开采中的成功实践。     

原油及馏分油脱酸技术进展

石油酸是原油和馏分油中普遍存在的腐蚀性物质，其主要成分为环烷酸并且含量可以高达90%以上。环烷酸具有羧酸的所有化学性质，所以常常造成严重的腐蚀，从而影响原油加工设备及油品使用设备的正常运行和使用寿命。随着近年来世界范围内高酸原油产量的逐渐增加，高原油及各种高酸值馏分油所带来的腐蚀与产品质量问题显得愈发严重，因此迫切需要开发出经济高效的脱酸技术与工艺路线。本文较为全面而详细地总结并评述了国内外原油及油品的各种脱酸技术方法。分析表明：目前所报道的各类脱酸工艺较多，其中工业应用的加氢脱酸效果虽好但是成本较高，而其他大多数脱酸方法都存在较多的缺点或不足，因此探寻一种绿色环保、经济高效并且具有较好普适性的油品脱酸工艺显得非常迫切而必要。酯化法脱酸具有加工工艺简单、不需要复杂的后继处理，几乎可以降低所有的高酸值原油和油品（轻质、重质馏分油以及渣油）的酸值，为原料油的进一步加工提供了方便。酯化脱酸工艺的关键在于高效催化剂的选择，而目前的催化酯化体系虽然脱酸率较高，但仍存在着反应时间较长的不足，相信通过反应过程强化等手段解决该问题以后，催化酯化脱酸工艺会被很快投入到原油及油品的脱酸实际工业生产中去。     

The role of smart packaging system in food supply chain

Food supply chain is a rapidly growing integrated sector and covers all the aspects from farm to fork, including manufacturing, packaging, distribution, storing, as well as further processing or cooking for consumption. Along this chain, smart packaging could impact the quality, safety, and sustainability of food. Packaging systems have evolved to be smarter with integration of emerging electronics and wireless communication and cloud data solutions. Although there are many factors causing the loss and waste issues for foods throughout the whole supply chain of food and there have been several articles showing the recent advances and breakthroughs in developing smart packaging systems, this review integrates these conceptual frameworks and technological applications and focuses on how innovative smart packaging solutions are beneficial to the overall quality and safety of food supply by enhancing product traceability and reducing the amount of food loss and waste. We start by introducing the concept of the management for the integrated food supply chain, which is critical in tactical and operational components that can enhance product traceability within the entire chain. Then we highlight the impact of smart packaging in reducing food loss and waste. We summarize the basic information of the common printing techniques for smart packaging system (sensor and indicator). Then, we discuss the potential challenges in the manufacturing and deployment of smart packaging systems, as well as their cost-related drawbacks and further steps in food supply chain.     

覆岩结构类型与开采覆岩损害特征分析

煤层开采打破了上覆岩层原有的平衡,必然引起岩层的移动、破断,导致应力场和裂隙场的改变,工作面出现矿压显现。上覆岩层的岩性和组合结构对工作面开采覆岩损害特征分布影响显著,一般岩性越坚硬,上覆岩层应力集中程度越高,采动裂隙越发育,矿压显现也越明显;坚硬岩层尤其是关键层对覆岩的破断运动起控制作用,覆岩破断发展到一定层位后软弱岩层往往是抑制覆岩破断进一步向上发展的关键。当工作面上覆岩层同时存在远近场关键层时,近场关键层的周期性破断引起裂隙带范围内岩层的运动和工作面周期来压;而远场关键层的周期性破断导致地表裂缝或台阶下沉,工作面压力急剧上升,有时甚至导致煤矿动压灾害,尤其是远近场关键层同步破断时动力现象更明显。通过地面钻孔使远场关键层提前破断是防止此类动力灾害的关键。     

Title加TextRank抽取关键句的情感分类研究

考虑到不同句子对判断文档情感倾向的重要程度不同，因而区分文档的关键句和细节句将有助于提高情感分类的性能。同时，考虑到Title和上下文信息，提出了一种基于Title和加权TextRank抽取关键句的情感分析方法SKTT，实现了高效的情感分析。根据文档Title的情感权重计算Title贡献度，考虑到标点和语义规则对情感倾向的影响；根据加权TextRank算法思想，在文档正文中构建了一个情感句有向图来提取关键句；计算所有关键句的情感倾向进行情感分类。在4个领域上进行实验，实验结果表明，该SKTT方法性能明显优于Baseline，具有高效性。     

一种标准模型下无证书签名方案的安全性分析与改进

无证书签名具有基于身份密码体制和传统公钥密码体制的优点，可解决复杂的公钥证书管理和密钥托管问题.Wu和Jing提出了一种强不可伪造的无证书签名方案，其安全性不依赖于理想的随机预言机.针对该方案的安全性，提出了两类伪造攻击.分析结果表明，该方案无法实现强不可伪造性，并在"malicious-but-passive"的密钥生成中心攻击下也是不安全的.为了提升该方案的安全性，设计了一个改进的无证书签名方案.在标准模型中证明了改进的方案对于适应性选择消息攻击是强不可伪造的，还能抵抗恶意的密钥生成中心攻击.此外，改进的方案具有较低的计算开销和较短的私钥长度，可应用于区块链、车联网、无线体域网等领域.     

面向Ad Hoc网络的无证书认证组密钥协商协议

安全和效率是影响无证书认证组密钥协商协议能否在Ad Hoc网络中得到实际应用的两个关键因素。针对这两个关键因素，以提高Ad Hoc网络安全组通信的安全性和效率为目标，提出一个无证书认证组密钥协商协议，基于椭圆曲线密码体制（ECC）点乘运算实现无配对的无证书认证组密钥协商和身份认证；并使用Huffman密钥树优化通信轮数，以降低计算量和通信量，提高组密钥协商效率。安全分析和性能分析表明，与现有基于无证书的组密钥协商协议相比，所提方案在组密钥协商时具有较高的效率和安全性，可以满足资源受限条件下组密钥建立以及组成员变动带来的密钥更新问题。     

Manufacture of Multilayered Artificial Cell Membranes through Sequential Bilayer Deposition on Emulsion Templates

Efforts to manufacture artificial cells that replicate the architectures, processes and behaviours of biological cells are rapidly increasing. Perhaps the most commonly reconstructed cellular structure is the membrane, through the use of unilamellar vesicles as models. However, many cellular membranes, including bacterial double membranes, nuclear envelopes, and organelle membranes, are multilamellar. Due to a lack of technologies available for their controlled construction, multilayered membranes are not part of the repertoire of cell-mimetic motifs used in bottom-up synthetic biology. To address this, we developed emulsion-based technologies that allow cell-sized multilayered vesicles to be produced layer-by-layer, with compositional control over each layer, thus enabling studies that would otherwise remain inaccessible. We discovered that bending rigidities scale with the number of layers and demonstrate inter-bilayer registration between coexisting liquid–liquid domains. These technologies will contribute to the exploitation of multilayered membrane structures, paving the way for incorporating protein complexes that span multiple bilayers.